The Immunohistochemistry Facility (IHC) provides support for basic research in cellular structure/function, as well as translational research in clinical applications and molecular medicine. The IHC serves the faculty in the Cancer Research Center by providing state-of-the-art immunohistochemistry and immunofluorescence technology, as well as primary processing of tissues for histologic sectioning and routine hematoxylin and eosin staining. The Facility has three goals: (1) to provide routine histologic and immunohistochemical services in a timely manner using cutting-edge technology and expertise;(2) to evaluate and implement new techniques and stains for development; and (3) to provide education. Routine services include processing of tissues to paraffin blocks, paraffin and frozen sections, routine hematoxylin and eosin staining, and a variety of immunohistochemical and immunofluorescent stains utilizing state-of-the-art instrumentation and a broad array of available characterized antibodies. Technology and application development is nurtured by a close relationship with Cancer Research Center investigators who produce novel antibodies and reagents in the course of their research. The laboratory also is an educational resource for investigators and graduate students who are unfamiliar with handling animal tissues and/or with the techniques used by the Core Facility;this activity frequently requires consultation, one-on-one training sessions, and advice on protocol development. Overall usage of the IHC has increased significantly since the 2001 CCSG submission with significant recent expansion;the number of projects performed in 2006 totaled three times the number performed the previous year. Currently, over 35 peer-reviewed UCCRC investigators across all six Scientific Programs routinely utilize the IHC, totaling 70% of Facility usage.